Continuous Intravenous Heparin Compared with Intermittent Subcutaneous Heparin in the Initial Treatment of Proximal-Vein Thrombosis

TLDR

A randomized double‑blind trial enrolled 115 patients with acute proximal deep‑vein thrombosis to compare continuous intravenous heparin with intermittent subcutaneous heparin as initial therapy. Continuous intravenous heparin achieved a therapeutic anticoagulant response in most patients and reduced recurrent venous thromboembolism to 5.2% versus 19.3% with subcutaneous heparin, demonstrating its superior efficacy linked to adequate anticoagulation levels. Published in N Engl J Med 1986; 315:1109–14.

Abstract

We performed a randomized double-blind trial comparing continuous intravenous heparin with intermittent subcutaneous heparin in the initial treatment of 115 patients with acute proximal deep-vein thrombosis. Intermittent subcutaneous heparin as administered in this trial was inferior to continuous intravenous heparin in preventing recurrent venous thromboembolism. The subcutaneous heparin regimen induced an initial anticoagulant response below the target therapeutic range in the majority of patients and resulted in a high frequency of recurrent venous thromboembolism (11 of 57 patients, 19.3 percent), which was virtually confined to patients with a subtherapeutic anticoagulant response. In contrast, continuous intravenous heparin induced a therapeutic anticoagulant response in the majority of patients and a low frequency of recurrent events (3 of 58 patients, 5.2 percent; P = 0.024); the recurrences were limited to patients with an initial subtherapeutic anticoagulant response. The results of this trial establish the efficacy of intravenous heparin in the treatment of proximal venous thrombosis and suggest a relation between the effectiveness of heparin and the levels of anticoagulation achieved; such a relation could explain the observed failure of the subcutaneous regimen. (N Engl J Med 1986; 315:1109–14.)